Gradient oxygen barrier coating modified by utilizing rare earth doped binary boride and preparation method of gradient oxygen barrier coating

The invention discloses a rare earth doped binary boride modified gradient oxygen barrier coating and a preparation method thereof. The coating comprises a matrix layer, a transition layer and a self-growing glass layer, the matrix layer comprises a graphite substrate material, the transition layer comprises a rare earth doped binary boride and a silicon carbide material, and the self-growing glass layer comprises an Hf-La-B-Si-O material; the problems of high sintering temperature, high material preparation difficulty, energy waste, high-temperature oxidation loosening, low anti-oxidation protection temperature and the like of an existing HfB2-SiC binary phase ceramic coating are solved, and the method has the advantages of reducing the sintering temperature, simplifying the material preparation difficulty, saving energy consumption, reducing the production cost and the like. The coating structure densification is improved, the internal defects of the coating are reduced, the oxidation activity and oxidation